Snippets tagged comma

Stumbled upon this challenge and tried my hand: http://themechanicalbride.blogspot.com/2009/04/f-solution-to-eric-lippert-challenge.html
The original challenge calls for a string result, so there's no issue with converting the sequence to a list from the outset since we need to enumerate it completely anyway; had it insisted on returning a sequence my answer would be different.
> commaize ["ABC"; "DEF"; "G"; "H"];;
val it : string = "ABC, DEF, G and H"